Currently, mobile communication technologies tend to provide highrate multimedia services increasingly.
FIG. 1 is a schematic diagram illustrating a System Architecture Evolution (SAE) system according to the related art.
Referring to FIG. 1, in the SAE system, a User Equipment (UE) 101 is a terminal device for receiving data. An Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a radio access network which includes an eNodeB/NodeB for providing a radio network interface for the UE. A Mobile Management Entity (MME) 103 is adapted to manage mobility contexts, session contexts and security information of the UE. A Serving Gateway (SGW) 104 is adapted to provide functions of a user plane. The MME 103 and the SGW 104 may be in the same physical entity. A Packet Gateway (PGW) 105 is adapted to implement charging and legal monitoring functions. The PGW 105 and the SGW 104 may be in the same physical entity. A Policy and Charging Rules Function (PCRF) 106 is adapted to provide Quality of Service (QoS) policies and charging rules. A Service GPRS Supporting Node (SGSN) 108 is a network node device for providing routing for data transmission in a Universal Mobile Telecommunications System (UMTS). A Home Subscriber Server (HSS) 109 is a home sub-system of the UE and is adapted to protect user information including the current location of the UE, the address of a serving node, user security information and packet data contexts of the UE.
FIG. 2 is a flowchart illustrating a UE Attach process according to the related art.
Referring to FIG. 2, at operation 201, a UE transmits an Attach Request to an MME. The Attach Request is transmitted to the MME through an evolved Node B (eNB) by using a Radio Resource Control (RRC) message and an S1 message.
At operation 202, the MME transmits a Create Session Request to a SGW/PGW. If the SGW and the PGW are separated, the signaling process between the SGW and the PGW is omitted herein.
At operation 203, the SGW/PGW transmits a Create Session Response to the MME. The Create Session Response includes a transport layer address and an uplink Tunnel Endpoint Identifier (TEID) of an S1 interface assigned by the SGW for each bearer of the UE. The transport layer address may be an Internet Protocol version 4 (IPv4) and/or an Internet Protocol version 6 (IPv6).
At operation 204, the MME transmits an Initial Context Setup Request to the eNB. The Initial Context Setup Request includes the transport layer address and the uplink TEID of the S1 interface assigned by the SGW for each bearer of the UE. The transport layer address may be the IPv4 and/or the IPv6.
At operation 205, the eNB transmits an RRC connection reconfiguration message to the UE.
At operation 206, the UE transmits an RRC connection reconfiguration response to the eNB.
At operation 207, the eNB transmits an Initial Context Setup Response to the MME. The Initial Context Setup Response includes a transport layer address and a downlink TEID of the S1 interface assigned by the eNB for each bearer of the UE. The transport layer address may be the IPv4 and/or the IPv6.
At operation 208, the UE transmits a Direct Transfer message to the eNB.
At operation 209, the eNB transmits a Non access stratum (NAS) message Attach complete message to the MME.
In this operation, the eNB transmits the Attach complete to the MME by using an S1 uplink direct transfer message.
At operation 210, the MME transmits a Bearer Modification Request to the SGW/PGW. The Bearer Modification Request includes the transport layer address and the downlink TEID of the S1 interface assigned by the eNB for each bearer of the UE, which are received from the eNB. The transport layer address may be the IPv4 and/or the IPv6.
At operation 211, the SGW/PGW transmits a Bearer Modification Response to the MME.
In technologies of the related art, the transport layer address transmitted from the SGW/PGW to the MME may be an IPv4 address or an IPv6 address or both the IPv4 address and the IPv6 address, and the S1 interface only has one IP address. When the IP address versions supported by the SGW and the eNB are different, issues to be addressed include how to establish a user plane bearer correctly and which node selects the IP version of the S1 interface.
Therefore, a need exists for a method and an apparatus for establishing a user plane bearer.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.